System for monitoring body chemistry

ABSTRACT

A system and method for monitoring body chemistry of a user, the system comprising: a housing supporting: a microsensor comprising a first and second working electrode, a reference electrode, and a counter electrode, and configured to access interstitial fluid of the user, and an electronics subsystem comprising a signal conditioning module that receives a signal stream, from the microsensor, wherein the electronics subsystem is configured to detect an impedance signal derived from two of the first working electrode, the second working electrode, the reference electrode, and the counter electrode; and a processing subsystem comprising: a first module configured to generate an analysis indicative of an analyte parameter of the user and derived from the signal stream and the impedance signal, and a second module configured to transmit information derived from the analysis to the user, thereby facilitating monitoring of body chemistry of the user.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/412,229, filed 23 Jan. 2017, which is a continuation of Ser. No.15/377,318, filed 13 Dec. 2016, which is a continuation of U.S. patentapplication Ser. No. 14/657,973, filed 13 Mar. 2015, which claims thebenefit of U.S. Provisional Application Ser. No. 61/952,594, filed on 13Mar. 2014, U.S. Provisional Application Ser. No. 62/012,874, filed on 16Jun. 2014, and U.S. Provisional Application Ser. No. 62/025,174, filedon 16 Jul. 2014, which are all incorporated herein in their entirety bythis reference.

TECHNICAL FIELD

This invention relates generally to the biometric device field, and morespecifically to a new and useful system for monitoring body chemistry inthe biometric device field.

BACKGROUND

Biomonitoring devices are commonly used, particularly byhealth-conscious individuals and individuals diagnosed with ailments, tomonitor body chemistry. Such biomonitoring devices perform the tasks ofdetermining an analyte level in a user's body, and providing informationregarding the analyte level to a user; however, these currentbiomonitoring devices typically convey information to users that islimited in detail, intermittent, and prompted by the command of theuser. Such biomonitoring devices, including blood glucose meters, arealso inappropriate for many applications outside of intermittent use,and place significant burdens on users (e.g., in requiring fingersticks, in requiring lancing, etc.) due to design and manufactureconsiderations. Additionally, current devices are configured to analyzeone or a limited number of analytes contributing to overall bodychemistry, due to limitations of sensors used in current biomonitoringdevices.

There is thus a need in the biometric device field to create a new anduseful system for monitoring body chemistry. This invention providessuch a new and useful system.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts elements of an embodiment of a system for monitoring bodychemistry;

FIGS. 2A and 2B depict embodiments of a microsensor patch, atransmitting unit, a housing, and an array of filaments in an embodimentof a system for monitoring body chemistry;

FIG. 2C depict a variation of electrodes in an embodiment of a systemfor monitoring body chemistry;

FIGS. 3A-3H depict examples of filament variations in an embodiment of asystem for monitoring body chemistry;

FIG. 4 depicts an embodiment of an electronics subsystem in anembodiment of a system for monitoring body chemistry;

FIGS. 5A-5C depict examples of a portion of an electronics subsystem inan embodiment of a system for monitoring body chemistry;

FIGS. 6A-6B depict examples of power management modules in an embodimentof a system for monitoring body chemistry;

FIG. 7 depicts a variation of an impedance detection module in anembodiment of a system for monitoring body chemistry;

FIG. 8 depicts an example of an applied voltage waveform in anembodiment of a system for monitoring body chemistry;

FIG. 9 depicts a variation of a housing in an embodiment of a system formonitoring body chemistry;

FIGS. 10A-10B depict specific examples of a housing in an embodiment ofa system for monitoring body chemistry;

FIG. 10C depicts a specific portion of a housing in an embodiment of asystem for monitoring body chemistry;

FIGS. 11A-11B depict examples of user interfaces implemented using asoftware module in an embodiment of a system for monitoring bodychemistry;

FIG. 12A depicts a notification module of an embodiment of a system formonitoring body chemistry;

FIGS. 12B-12C depict specific examples of notifications in an embodimentof a system for monitoring body chemistry;

FIG. 13 depicts communication between a processing subsystem and astorage module in an embodiment of a system for monitoring bodychemistry;

FIGS. 14A-14C depict examples of an arch application method and anend-to-end application method, respectively, in an embodiment of asystem for monitoring body chemistry;

FIGS. 15A-15B depict variations of a patch applicator in an embodimentof a system for monitoring body chemistry;

FIGS. 16A-16D depict a first specific example of a patch applicator inan embodiment of a system for monitoring body chemistry;

FIG. 17 depicts a second specific example of a patch applicator in anembodiment of a system for monitoring body chemistry;

FIGS. 18A-18B depict a specific example of a base station in anembodiment of a system for monitoring body chemistry;

FIG. 19 depicts operation modes of components of an embodiment of asystem for monitoring body chemistry; and

FIG. 20 depicts an embodiment of a method for monitoring body chemistry.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the inventionis not intended to limit the invention to these preferred embodiments,but rather to enable any person skilled in the art to make and use thisinvention.

1. System

As shown in FIG. 1, an embodiment of the system 100 for monitoring bodychemistry of a user comprises a housing 190 that supports a microsensor116 and an electronics subsystem 120 in communication with themicrosensor 116; and a processing subsystem 160 configured to generatean analysis indicative of an analyte parameter of the user, wherein theanalysis is derived from a signal stream of the microsensor and animpedance signal from the electronics subsystem. In more detail, thehousing 190, microsensor 116, and the electronics subsystem 120 can beconfigured as a microsensor patch 110 configured to sense analyte levelsin a user's body, wherein the electronics subsystem includes a signalconditioning module 122, a power management module 124, a storage module127, and a transmitting unit 130 in communication with the processingsubsystem 160 and/or an electronic device (e.g., mobile computing device150) associated with the user.

In some variations, the system 100 can further include a patchapplicator 180 configured to facilitate application of the microsensorpatch 110 onto the body of a user in a reliable manner. The system 100functions to provide continuous monitoring of a user's body chemistrythrough reception and processing of signals associated with one or moreanalytes present in the body of the user, and to provide an analysis ofthe user's body chemistry to the user and/or an entity (e.g., healthcare professional, caretaker, relative, friend, acquaintance, etc.)associated with the user. Alternatively, the system 100 can function todetect a user's body chemistry upon the user's request or sporadically,and/or can provide an analysis of the user's body chemistry only to theuser.

The system 100 is configured to be worn by the patient outside of aclinical (e.g., hospital) or research (e.g., laboratory) setting, suchthat the patient can be in a non-contrived environment as he or she isinterfacing with the microsensor patch 110 for monitoring of bodychemistry. Furthermore, elements of the system 100 can be reusable ordisposable (e.g., based upon modularity of the system 100), or theentire system 100 can be configured to be disposable. In one specificexample, the system 100 adheres to the patient (thus not compelling thepatient to hold any part of the system 100 by hand), has a low profilethat conforms to the patient, and is configured to receive and transmitsignals indicative of body chemistry parameters of the user, fordownstream analysis and information transfer to the user. Alternatively,the system 100 can be substantially non-portable, non-wearable, and/orintended for use in a clinical or research setting.

As indicated above and further below, elements of the system can beimplemented on one or more computer networks, computer systems, orapplications servers, etc. The computer system(s) can comprise one ormore of: a cloud-based computer, a mainframe computer system, agrid-computer system, or any other suitable computer system, and thecomputer system can support collection of data from a wearable deviceand/or a base station, processing of these data, and transmission ofalerts, notifications, and/or user interface updates to one or moreelectronic computing devices (e.g., mobile computing device, wrist-bornemobile computing device, head-mounted mobile computing device, etc.)linked to or affiliated with an account of the user. For example, thecomputer system can receive signals indicative of one or more analyteparameters of the user and distribute alerts and notifications over adistributed network, such as over a cellular network or over an Internetconnection. In this example, the computer system can upload alerts andnotifications to a native body chemistry monitoring applicationincluding the user interface and executing on a mobile computing deviceassociated with the user.

Additionally or alternatively, an electronic computing device (e.g., alaptop computer, a desktop computer, a tablet, a smartphone, a smartwatch, a smart eyewear accessory, a personal data assistant, etc.)associated with the system (e.g., with the account of the user) canmaintain the account of the user, create and maintain a user-specificmodel within the account, and execute a native body chemistry monitoringapplication (including the user interface) with functions including oneor more of: generating alerts or notifications, receiving alerts ornotifications, displaying alerts or notifications, updating predictionsof changes in state of the user, and any other suitable function thatenhances body chemistry monitoring of the user. The system 100 ispreferably configured to implement at least a portion of the method 200described in Section 2 below; however, the system 100 can additionallyor alternatively be configured to implement any other suitable method.

1.1 System—Microsensor Patch

As shown in FIG. 1, the microsensor patch 110 comprises a microsensor116 and an electronics subsystem 120 in communication with themicrosensor 116, wherein the microsensor 116 and the electronicssubsystem 120 are supported by a housing 190. The microsensor patch 110can be configured to detect and sense only a single analyte; however,the microsensor patch 110 can alternatively be configured to detect andsense multiple analytes in order to provide an analysis based onmultiple analytes. Preferably, the microsensor patch 110 is configuredto be disposable; however, the microsensor patch 110 can alternativelybe configured to be reusable for any suitable duration or number ofuses. In one variation, the microsensor patch 110 is configured to be asemi-permanent component (e.g., wearable for a week before replacement,wearable for a month before replacement, etc.) configured to sense theuser's body chemistry with minimal signal degradation for at a least aweek post-coupling of the microsensor patch 110 to the body of the user.However, in another variation, the microsensor patch 110 can beconfigured to be a permanent component configured to permanently coupleto a user. Modularity of the microsensor patch 110 is described infurther detail below.

1.1.1 System—Microsensor

The microsensor 116 of the microsensor patch 110 preferably comprises anarray of filaments 117, as shown in FIGS. 1 and 2A, and functions topenetrate skin of the user in order to sense one or more analytescharacterizing the user's body chemistry. Preferably, the array offilaments 117 is configured to penetrate the user's stratum corneum(i.e., an outer skin layer) in order to sense analytes withininterstitial (extracellular) fluid, which is throughout the body;however, the array of filaments 117 can be configured to penetrate theuser's skin to any other suitable depth. For instance, the microsensor116 can alternatively be configured to penetrate deeper layers, orvarious depth layers of a user's skin in order to sense analytes withinany appropriate bodily fluid of the user. The microsensor 116 can beconfigured to sense analytes/ions characterizing a user's body chemistryusing a potentiometric measurement (e.g., for small analytes includingpotassium, sodium calcium, etc.), using an amperometric measurement(e.g., for large analytes including glucose, lactic acid, creatinine,etc.), using a conductometric measurement, and/or using any othersuitable measurement.

Preferably, sensed analytes result in a signal (e.g., voltage, current,resistance, capacitance, impedance, gravimetric, etc.) detectable by theelectronics subsystem 120 in communication with the microsensor 116;however, analyte sensing can comprise any other appropriate mechanismusing the microsensor 116. As mentioned earlier, the microsensor 116 isalso preferably integrated with the electronics subsystem 120. In afirst variation, the microsensor 116 is coupled to the semiconductorarchitecture of the electronics subsystem 120 (e.g., the microsensor 116is coupled to an integrated circuit comprising the electronics subsystem120), in a second variation, the microsensor 116 is more closelyintegrated into the semiconductor architecture of the electronicssubsystem 120 (e.g., there is closer integration between the microsensor116 and an integrated circuit including the electronics subsystem 120),and in a third variation, the microsensor 116 and the electronicssubsystem 120 are constructed in a system-on-a-chip fashion (e.g., allcomponents are integrated into a single chip). As such, in somevariations, filaments the array of filaments 117 of the microsensor 116can be directly or indirectly integrated with electronics components,such that preprocessing of a signal from the microsensor 116 can beperformed using the electronics components (e.g., of the array offilaments 117, of the electronics subsystem 120) prior to or aftertransmitting signals to the electronics subsystem 120 (e.g., to ananalog front end, to an analog to digital converter). The electronicscomponents can be coupled to a filament substrate, or otherwiseintegrated with the filaments in any suitable fashion (e.g., wired,using a contact pad, etc.). Alternatively, the electronics componentscan be fully integrated into the electronics subsystem 120 andconfigured to communicate with the microsensor 116, or the electronicscomponents can be split between the microsensor and the electronicssubsystem 120. The microsensor 116 can, however, comprise any othersuitable architecture or configuration.

The microsensor 116 preferably senses analyte parameters using the arrayof filaments 117, such that absolute values of specific analytes/ionscan be detected and analyzed. The microsensor 116 can additionally beconfigured to sense analyte parameters using the array of filaments 117,such that changes in values of specific analyte/ion parameters orderivatives thereof (e.g., trends in values of a parameter, slopes ofcurves characterizing a trend in a parameter vs. another parameter,areas under curves characterizing a trend, a duration of time spentwithin a certain parameter range, etc.) can be detected and analyzed. Inone variation, sensing by the microsensor 116 is achieved at a lowfrequency at discrete time points (e.g., every minute, or every hour),and in another variation, sensing by the microsensor 116 is achievedsubstantially continuously at a high frequency (e.g., every picosecond,every millisecond, every second). In one specific example for bloodchemistry analysis, the array of filaments 117 of the microsensor 116 isconfigured to sense one or more of: electrolytes, glucose, bicarbonate,creatinine, body urea nitrogen (BUN), sodium, iodide, iodine andpotassium of a user's blood chemistry. In another specific example, thearray of filaments 117 of the microsensor 116 is configured to sense atleast one of biomarkers, cell count, hormone levels, alcohol content,gases (e.g. carbon dioxide, oxygen, etc.), drugconcentrations/metabolism, pH and analytes within a user's body fluid.

As shown in FIG. 2A, the array of filaments 117 is preferably located atthe base surface of the microsensor patch 110, and functions tointerface directly with a user in a transdermal manner (e.g., inaccessing interstitial fluid) in order to sense at least one analyte/ioncharacterizing the user's body chemistry. The array of filaments 117 ispreferably arranged in a uniform pattern with a specified densityoptimized to effectively penetrate a user's skin and provide anappropriate signal, while minimizing pain to the user. Additionally, thearray of filaments 117 can be arranged in a manner to optimize couplingto the user, such that the microsensor firmly couples to the user overthe lifetime usage of the system. For example, the filaments 118 cancomprise several pieces and/or be attached to a flexible base to allowthe array of filaments 117 to conform to a user's body. In onevariation, the array of filaments 117 is arranged in a rectangularpattern, and in another variation, the array of filaments 117 isarranged in a circular or ellipsoid pattern. However, in othervariations, the array of filaments 117 can be arranged in any othersuitable manner (e.g., a random arrangement). The array of filaments 117can also be configured to facilitate coupling to a user, by comprisingfilaments of different lengths or geometries. Having filaments 118 ofdifferent lengths can further function to allow measurement of differentions/analytes at different depths of penetration (e.g., a filament witha first length can sense one analyte at a first depth, and a filamentwith a second length can sense another analyte at a second depth). Thearray of filaments 117 can also comprise filaments 118 of differentgeometries (e.g., height, diameter) to facilitate sensing ofanalytes/ions at lower or higher concentrations. In one specificexample, the array of filaments 117 is arranged at a density of 100filaments per square centimeter and each filament 118 in the array offilaments 117 has a length of 250-350 microns, which allows appropriatelevels of detection, coupling to a user, and pain experienced by theuser.

Each filament 118 in the array of filaments 117 preferably functions tosense a single analyte; however, each filament 118 in the array offilaments 117 can additionally be configured to sense more than oneanalyte. Furthermore, the array of filaments 117 can be furtherconfigured, such that a subarray of the array of filaments 117 functionsas a single sensor configured to sense a particular analyte orbiomarker, as shown in FIG. 2B. Furthermore, any configuration ofsubarrays of the array of filaments 117 can additionally oralternatively be configured as one or more of: a working electrode, acounter electrode (i.e., auxiliary electrode), and a referenceelectrode, for instance, in a two-electrode cell, a three-electrodecell, or a more-than-three-electrode cell. In one variation, as shown inFIG. 2C, the array of filaments 117 of the microsensor 116 is configuredas a first working electrode 11 (corresponding to a first subarray offilaments), a second working electrode 12 (corresponding to a secondsubarray of filaments), a counter electrode 13 (corresponding to a thirdsubarray of filaments), and a reference electrode 14 (corresponding to afourth subarray of filaments). In a specific example of this variation,each subarray associated with the first working electrode 11, the secondworking electrode 12, the counter electrode 13, and the referenceelectrode 14, respectively, is substantially identical in morphology(e.g., area of the microsensor). Furthermore, in the specific example,each subarray has a square footprint, and the subarrays are configuredin a 2×2 arrangement to define a larger square footprint. However, thearray of filaments 117 can be configured as one or more of: a workingelectrode, a counter electrode, and a reference electrode in any othersuitable manner, and can furthermore have any other suitablemorphology(ies) and/or configuration relative to each other.

Additionally or alternatively, any subarray of the array of filaments117 can be configured to release biomaterials (e.g., therapeuticsubstances, drugs) for treating a medical condition of a user (e.g., asfacilitated by biomaterial dissolution in interstitial fluid). Multiplesubarrays of the array of filaments can then be configured to sensedifferent analytes/biomarkers, or the same analyte/biomarker.Furthermore, a subarray or a single filament 118 of the array offilaments 117 can be configured as a ground region of the microsensor116, such that signals generated by the microsensor 116 in response toanalyte detection can be normalized by the signals generated by thesubarray or single filament 118 serving as a ground region. Preferably,all subarrays of the array of filaments 117 are substantially equal insize and density; however, each subarray of the array of filaments 117can alternatively be optimized to maximize signal generation anddetection in response to a specific analyte. In an example, analytesthat are known to have a lower concentration within a user's body fluidcan correspond to a larger subarray of the array of filaments 117. Inanother example, analytes that are known to have a higher concentrationwithin a user's body fluid can correspond to a smaller subarray of thearray of filaments 117. In one extreme example, an entire array offilaments can be configured to sense a single analyte, such that themicrosensor 116 and microsensor patch 110 is configured to sense anddetect only one analyte. In another extreme example, each singlefilament in an array can be configured to detect a single analyteallowing for detection of multiple analytes within a single array (e.g.,for a 100-filament array, 100 analytes can be tested).

In other variations, a subarray of the array of filaments 117 can alsobe used to detect other physiologically relevant parameters, such aselectrophysiological signals (e.g., electrocardiogram,electroencephalogram), body temperature, respiration, and skin impedancechange (e.g., to measure hydration state or inflammatory response). Inthese other variations, the subarray can be dedicated to measuring thesephysiologically relevant parameters, which could be combined withanalyte/ion parameter measurements in order to provide meaningfulinformation to a user. As an example, the simultaneous measurement ofpotassium levels and electrocardiogram measurements, enabled bysubarrays of the array of filaments 117, can provide a more completediagnosis of cardiovascular problems or events than either measurementby itself.

A filament 118 of the array of filaments can comprise one or more of: asubstrate core, the substrate core including a base end coupled to thesubstrate, a columnar protrusion having a proximal portion coupled tothe base end and a distal portion, and a tip region coupled to thedistal portion of the columnar protrusion and that facilitates access tothe body fluid of the user; a conductive layer, isolated to the tipregion of the substrate core and isolated away from the base end and thecolumnar protrusion as an active region that enables transmission ofelectronic signals generated upon detection of an analyte; an insulatinglayer ensheathing the columnar protrusion and base end of the substratecore and exposing a portion of the conductive layer, thereby defining aboundary of the active region; a sensing layer, in communication withthe active region, characterized by reversible redox behavior fortransduction of an ionic concentration of the analyte into an electronicsignal; an intermediate selective layer superficial to the conductivelayer and deeper than the sensing layer, relative to a most distal pointof the tip region of the filament, that facilitates detection of theanalyte; an intermediate protective layer, superficial to theintermediate selective layer, including a functional compound thatpromotes generation of a protective barrier; and a selective coatingsuperficial to the intermediate protective layer, having a distributionof molecules that respond to presence of the analyte, superficial to thesensing layer. Thus, a filament can comprise one or more regions,morphologies (examples of which are shown in FIGS. 3A-3H, with elements118 a-118 h), compositions, and/or configurations as described in U.S.Pub. No. 2014/0275897, entitled “On-Body Microsensor for Biomonitoring”and filed on 14 Mar. 2014 and/or U.S. App. No. 62/025,174, and entitled“System for Monitoring Body Chemistry” and filed on 16 Jul. 2014, whichare each incorporated herein in their entirety by this reference.However, the filament can additionally or alternatively comprise anyother suitable region, composition, morphology, and/or configuration.

1.1.2 System—Electronics Subsystem

The electronics subsystem 120 functions to receive analog signals fromthe microsensor 116 and to convert them into digital signals to beprocessed by a microprocessor 113 of the electronics subsystem 120. Inreceiving signals, processing signals, regulating function, storingdata, and/or transmitting data, the electronics subsystem 120 preferablyincludes a microprocessor 113 interfacing with one or more of: a signalconditioning module 122, a power management module 124, an impedancedetection module 126, a storage module 127, and a transmitting unit 130,as shown in FIG. 4. However, the electronics subsystem 120 canadditionally or alternatively include any other suitable modulesconfigured to facilitate signal reception, signal processing, and datatransfer in an efficient manner.

The microprocessor 113 preferably includes memory and/or is coupled to astorage module 127 (e.g., flash storage). The microprocessor 113 canalso include and/or be coupled to a clock/watchdog module (which can beincorporated into a microcontroller unit) for control of timing betweendifferent functions of the electronics subsystem 120. The microprocessor113 functions to process received signals, enable power distribution,enable impedance monitoring, and enable data transmission from theelectronics subsystem 120, in relation to other portions of theelectronics subsystem 120 described below; however, the microprocessor113 can alternatively or additionally be configured to perform any othersuitable function.

The signal conditioning module 122 functions to preprocess signalsdetected and received using the microsensor 116, thereby producingconditioned data prior to processing at the processing subsystem 160.The signal conditioning module 122 can include one or more of: a signalmultiplexer, an analog front end, an amplifier (e.g., a variable gainamplifier), a filter (e.g., low pass filter, high pass filter, band passfilter, etc.), an analog-to-digital converter (ADC), and adigital-to-analog converter (DAC). In one variation, as shown in FIG. 4,the signal conditioning module 122 comprises a multiplexer 22 incommunication with the microsensor 116, wherein the multiplexer 22 isconfigured to communicate an output to an analog front end 23 thatinterfaces the microsensor 116 with an ADC 24 by way of a variable gainamplifier 25 coupled to a filter 26. In a specific example of thisvariation, the analog front end 23 circuitry is configured with ashifted potential different than a reference potential of the referenceelectrode 14 of the microsensor 116, wherein the shifted potential isdifferent (e.g., −2V to 2V different) from the reference potential ofthe reference electrode 14. The configuration involving a differencebetween the shifted potential and the reference potential can allow thesystem 100 to drive redox reactions at the surface of the microsensor110. However, in alternative variations of the specific example, theanalog front end (or any other element of the signal conditioning module122) can be configured with any other suitable potential relative topotentials of electrodes of the microsensor 116.

In more detail, the multiplexer 22 of the signal conditioning module 122is preferably configured to receive multiple signals from themicrosensor 116 (e.g., from subarrays of the array of filaments 117) andto forward the multiple signals received at multiple input lines in asingle line at the analog front end. The multiplexer 22 thus increasesan amount of data that can be transmitted within a given time constraintand/or bandwidth constraint. The number of input channels to themultiplexer 22 is preferably greater than or equal to the number ofoutput channels of the microsensor 116, and can have any suitablerelationship between the number of input lines into the multiplexer 22,select lines of the multiplexer, and output lines from the multiplexer22. In some variations, the multiplexer 22 can include apost-multiplexer gain in order to reduce capacitance values of theanalog front end 23 coupled to the multiplexer 22, and which can also beused to limit a number of amplifiers of the electronics 120, such that asingle amplifier is coupled to the multiplexer 22 (as opposed toamplifiers coupled to each individual sensor); however, the multiplexer22 can alternatively not include any gain producing elements. In somevariations, the multiplexer 22 can additionally or alternatively includehigh frequency and/or low frequency limiting elements. However, themultiplexer 22 can additionally or alternatively be configured in anyother suitable manner. Furthermore, in alternative variations, thesignal conditioning module 122 can omit a multiplexer and/or comprise oromit any other suitable element.

In variations, an interface between the microsensor 116 and otherelements of the electronics subsystem 120 can be configured in a mannerthat prevents or otherwise reduces leakage current effects due to aredox potential of the microsensor 16 in relation to other elementselectronics subsystem 120. In a first configuration, a leakage currenteffect can result when a diode to ground (e.g., an ESD-diode to ground)is configured at an interface between the microsensor 116 and amultiplexer 22, as shown in FIG. 5A. To prevent or otherwise reduce theleakage current effect, a set of diodes 70, comprising a first diode 71(e.g., a first EST-diode) and a second diode 72 (e.g., a secondESD-diode), configured at an interface between the microsensor 116 andthe multiplexer 22 can be coupled to an element 73 (e.g., inductor,ferrite bead, resistor, etc.) that provides a high resistance totransient voltage spikes and directs any discharge through the seconddiode 72 to ground (instead of damaging the electronics subsystem 120),as shown in FIG. 5B. The multiplexer 22 can also comprise a switch 75,as shown in FIG. 5C, that allows altering of potentials within theanalog front end 23. As shown in FIG. 5C, eliminating a voltagedifference (i.e., between Vs and V2) eliminates or otherwise reducesleakage currents that can affect readings from the microsensor 110.

The power management module 124 functions to provide dynamic modulationof power transfer to and from elements of the microsensor patch 110, ina manner that enables efficient operation of the system 100. Preferably,the power management module 124 interfaces with a battery 138 andelements of the transmitting unit 130 requiring power (e.g., by way of amicroprocessor 113, as shown in FIG. 4), as described in further detailbelow. Additionally, the power management module 124 can furtherinterface with an external processing element of the processingsubsystem 160, such that the power management module 124 can be at leastpartially implemented in firmware. In one such variation of the powermanagement module 124, wherein power management is achieved in firmware,the power management module 124 can be configured to anticipate powerrequirements of one or more elements, and to automatically operate atthe highest demanded power mode (e.g., voltage) required, while neverdropping below a minimum power level required by the elements. The powermanagement module 124 can also facilitate efficient switching ofcomponents to an “off” state when not needed, in order to contribute tolower current consumption. Additionally or alternatively, the powermanagement module 124 can be configured to dynamically trigger highcurrent draw sensing components (e.g., the impedance detection module126) to an “on” state, only when needed, by monitoring other systemcomponents (e.g., voltage of a counter electrode 13).

In an example, as shown in FIG. 6A, a group of elements requiringdifferent operating power levels can be coupled to the power managementmodule 124, and the power management module 124 can output power at thehighest operating power level anticipated among the elements. Disparateelements can also set a minimum level of power they require, and aselements vary their power requirements, the power management module 124can then automatically adjust power output such that a power levelprovided never drops below the lowest power level required. In thisvariation, elements of the microsensor patch 110 requiring power arethus dynamically provided with their highest demanded power level, tosubstantially limit energy wasted by the system 100 and to satisfy powerlevel requirements of all running elements. In another variation of thepower management module 124, wherein power management is achieved infirmware, the power management module 124 can be configured to detectelements requiring power, and to automatically operate at the highestdemanded power mode (e.g., voltage) required. In an example, a group ofelements requiring different operating voltages can be detected, and thepower management module 124 can output power at the highest operatingvoltage detected. As elements vary their voltage requirements, the powermanagement module 124 can then automatically adjust voltage output tomeet the highest demanded voltage. In this variation, elements of themicrosensor patch 110 requiring power are thus dynamically provided withtheir highest demanded voltage, to substantially limit energy wasted bythe system 100.

In other variations, power management can be achieved by the powermanagement module 124 without implementation in firmware, such thatpower management occurs in circuitry. In these other variations, anexample of which is shown in FIG. 6B, power management can compriseproviding a set amount of power to elements requiring power, andcompletely eliminating power transfer to elements not requiring power.The system 100 can, however, comprise any other suitable variation ofthe power management modules 124.

In relation to the power management module 124, the electronicssubsystem 120 can comprise a battery 138, which functions to serve as apower source for the electronics subsystem 120. The battery 138 ispreferably coupled to a fuel gage 38 and a charging detection module 39,each of which is coupled to the microprocessor 113 (described in furtherdetail below). The battery 138 is preferably a lithium-ion battery thatis configured to be rechargeable, but can be any appropriaterechargeable battery (e.g., nickel-cadmium, nickel metal hydride, orlithium-ion polymer). Alternatively, the battery 138 may not be arechargeable battery. Preferably, the battery 138 is configured to havea profile with a low aspect ratio, contributing to a thin form factor ofthe microsensor patch 110. However, the battery 138 can be configured tohave any appropriate profile such that the battery 130 provides adequatepower characteristics (e.g., cycle life, charging time, discharge time,etc.) for the system 100. In some variations, a thin-film battery can beintegrated with the microsensor patch 110 in order to facilitatesubstantially continuous analyte detection by the system 100,independent of the microprocessor 113 and digital electronics of theelectronics subsystem 120.

In embodiments where the battery 138 is rechargeable, the electronicssubsystem 120 can also comprise a charging coil 140 that functions toprovide inductive charging for the battery 138, and a charging detectionmodule 39, in communication with the microprocessor 113, that enabledetection of charging of the battery 138. The charging coil 140 ispreferably coupled to the battery 138 and converts energy from anelectromagnetic field (e.g., provided by an element of a base station,as described in further detail below), into electrical energy to chargethe battery 138. Inductive charging provided by the charging coil 140thus facilitates user mobility while interacting with the system 100. Inalternative variations, however, the charging coil 140 can altogether beomitted (e.g., in embodiments without a rechargeable battery), orreplaced by a connection configured to provide wired charging of arechargeable battery.

Additionally or alternatively, in some variations, the microsensor patch110 can comprise a semi-active or fully-active power cell (e.g.,implementing microelectromechanical system elements) that functions toabsorb and/or release generated energy from any one or more of: bodyheat of the user, body movement of the user (e.g., with piezoelectricelements, with capacitive elements), static voltage from the environmentof the user, light in the environment of the user (e.g., using solarcells), magnetic energy flux, galvanic differentials, and any othersuitable energy source to provide secondary backup energy for the system100.

The impedance detection module 126 is in communication with the signalconditioning module 122 and the power management module 124, andfunctions to enable detection of a proper interface between themicrosensor 116 and body fluid (e.g., interstitial fluid) of the user.In facilitating monitoring of impedance, the impedance detection module126 can thus provide signals that indicate that the microsensor patch110 is properly coupled to the user (e.g., interfacing with interstitialfluid and experiencing an ˜80% moisture environment) or improperlycoupled to the user (e.g., not interfacing properly with interstitialfluid and experiencing a low-moisture environment). Signals from theimpedance detection module 126 can further be used to trigger an errorcorrection action (e.g., notification for the user to reapply themicrosensor patch 110, automatic manipulation of the microsensor patch110 to re-establish interface with body fluid, etc.). In one variation,as shown in FIG. 4, the impedance detection module can compriseelectronic circuitry configured to communicate with the multiplexer 22,the ADC 24, and the power management module 124, in receiving animpedance signal from the microsensor 116. However, the impedancedetection module 126 can additionally or alternatively be configuredrelative to other elements of the electronics subsystem 120 in any othersuitable manner.

In generating the impedance signal, the impedance detection module 126can be configured to detect impedance between two electrodes of thearray of filaments 117 in response to an applied voltage provided incooperation with the power management module 126 and the microprocessor113. In one variation, wherein the microsensor 116 comprises a firstworking electrode 11, a second working electrode 12, a counter electrode13, and a reference electrode, the impedance detection module 126 can beconfigured to detect impedance from two of the first working electrode11, the second working electrode 12, the counter electrode 13, and thereference electrode 14, examples of which are shown in FIG. 7. In aspecific example, an applied signal can be injected into the system in aworking electrode and detected in the reference electrode 14. However inother configurations of the microsensor 116, the impedance detectionmodule 126 can be configured to detect impedance from electrodes of themicrosensor 116 in any other suitable manner.

In relation to the applied voltage used for generation and reception ofthe impedance signal (i.e., for purposes of perturbation), theelectronics subsystem 120 is preferably configured to provide an appliedvoltage waveform having a characteristic value (e.g., average value)near the operating potential of the signal conditioning module 122 ofthe electronics subsystem 120. In a variation wherein the signalconditioning module 122 (e.g., an analog front end 23 of the signalconditioning module 122) operates at a shifted potential relative to apotential of an electrode of the microsensor 116 (e.g., a referencepotential of a reference electrode), the applied voltage waveformpreferably has a characteristic value (e.g., average value) near orequal to that of the shifted potential, in order to improve stability ofthe microsensor 110 when switching back to a current sensing mode (i.e.,the primary detection mode). The offset (i.e., shifted potential) isconfigured to reduce or minimize any disruption to signal integrity whenthe microsensor 110 is switched from a current sensing mode to animpedance detection mode, and then back to a current sensing mode. In aspecific example, as shown in FIG. 8, the applied voltage waveform isshifted about a characteristic value and has a frequency from 50-200kHz, in relation to a shifted potential of the analog front end 23relative to the reference electrode 14. However, the applied voltage canalternatively have any other suitable characteristics (e.g.,characteristic voltage values, frequencies, etc.) defined in relation tothe operating potential(s) of any other suitable element of theelectronic subsystem 120 related to the microsensor 116.

In relation to triggering of a measurement using the impedance detectionmodule 126, triggering can occur with any suitable frequency (e.g., inrelation to the lifespan of usage of the system 100), any suitableregularity (e.g., at regular time intervals, at irregular timeintervals, etc.), and/or upon any suitable triggering event. In onevariation, the impedance detection module 126 can be configured toprovide an impedance signal in association with monitoring of anelectrode (e.g., monitoring voltage of the counter electrode 13) of themicrosensor 116, wherein detection of an out-of-range parameter (e.g.,voltage) of the electrode triggers the applied voltage waveform andgeneration of an impedance signal. As such, the electronics subsystem120 and the processing subsystem 160 (described further below) can beconfigured to cooperate in continuously detecting a voltage parameter ofthe counter electrode 13, and the electronics subsystem 120 can beconfigured to apply the applied voltage waveform and detect theimpedance signal when the voltage parameter of the counter electrodesatisfies a voltage threshold condition.

Additionally or alternatively, in another variation, the impedancedetection module 126 can be configured to provide an impedance signalupon initial application of the system 100 to the body of the user.Additionally or alternatively, in another variation, the impedancedetection module 126 can be configured to provide impedance signals atregular time intervals (e.g., once every hour) over the course of use ofthe system 100 by the user. Additionally or alternatively, in relationto other sensors (e.g., of a mobile computing device associated with theuser and the system 100, of a wearable computing device associated withthe user and the system 100, of the system 100, etc.) the impedancedetection module 126 can be configured to provide an impedance signal inresponse to a sensor signal that indicates performance of an action bythe user. For instance, monitoring of signals provided by anaccelerometer and/or gyroscope can be used to indicate that the user isexercising, and that an impedance measurement should be taken (e.g.,during exercise, after exercise, etc.) to ensure proper coupling of thesystem 100 to the user. In another example, monitoring of bodytemperature of the user can be used to indicate that the user isshowering, and that an impedance measurement should be to ensure propercoupling of the system 100 to the user. The impedance detection module126 can, however, be configured in any other suitable manner.

The impedance detection module 126 can further be used to generatenotifications pertaining to impedance signal measurements that indicateimproper coupling. For instance, a notification can be generated (andtransmitted to a mobile computing device of the user) in response todetection of unsuitable impedance derived from comparison between theimpedance signal and an impedance threshold condition. However, use ofthe impedance signal in performing an error correction action can beperformed in any other suitable manner.

The transmitting unit 130 functions to receive signals generated by themicrosensor patch 110 (e.g., by way of the microprocessor 113), and tointerface with at least one of a mobile computing device 150, a dataprocessing and/or storage module (e.g., a module external to an on-boardstorage module, a cloud-based computing module, etc.) by outputtingsignals based on at least one analyte parameter. The transmitting unit130 thus cooperates with other elements of the electronics subsystem 120to transmit signals based on sensed analyte parameters, which can beused to facilitate analyses of the user's body chemistry. In variations,the transmitting unit 130 includes an antenna 132, a radio 134 couplingthe antenna to the microprocessor 113, and can additionally oralternatively include a linking interface 136 (e.g., wireless or wiredinterface, as described in further detail below).

Preferably, the transmitting unit 130 and the microsensor patch 110 areintegrated as a cohesive unit; however, the transmitting unit 130 andthe microsensor patch 110 can alternatively form a modular unit, whereinone of the transmitting unit 130 and the microsensor patch 110 isdisposable, and wherein one of the transmitting unit 130 and themicrosensor patch 110 is reusable. In variations of the microsensorpatch 110 and the transmitting unit 130, elements of the microsensorpatch 110 aside from the microsensor 116 can alternatively be integratedwith the transmitting unit 130, such that the transmitting unit 130 isconfigured to be reusable and the microsensor 116 of the microsensorpatch 110 is configured to be disposable. Modularity in the system 100is described in further detail in relation to the housing 190 below.

Additionally, the transmitting unit 130 is preferably configured tooutput signals based on at least one analyte parameter characterizingbody chemistry continuously over the lifetime usage of the transmittingunit 130; however, the transmitting unit 130 can alternatively beconfigured to output signals based on at least one analyte parameter ata set of time points (e.g., minutes, hours, days). Still alternatively,the transmitting unit 130 can be configured to output signals in amanner that does not interfere with other operations (e.g., signalcollection operations) of the electronics subsystem 120. In one suchexample, the transmitting unit 130 can be configured to stop signaltransmission whenever the ADC 24 is collecting signal data from themicrosensor 116, in coordination with timing enabled by a clock/watchdogmodule associated with the microprocessor 113. In variations, thetransmitting unit 130 can be further configured to output signals upon auser prompt, and/or can comprise a variable sampling rate. For example,the sampling rate can be lower when user is asleep, higher duringactivity (e.g., exercise), higher when there is a sudden change in avalue, higher in response to other stimuli (e.g., if glucose spikes,sampling rate increases for all analytes).

The antenna 132 of the transmitting unit 130 functions to convertelectrical signals from the microsensor patch 110 into radio waves, tofacilitate communication with one or more devices external to themicrosensor patch 110 and/or transmitting unit 130 assembly (e.g., by aBluetooth Low Energy connection). The antenna 132 preferably interfaceswith a radio 134 coupled to the microprocessor 113, as shown in FIG. 4,but can additionally or alternatively interface with other elements ofthe transmitting unit 130. The antenna is preferably an omnidirectionalantenna that radiates radio wave power uniformly primarily in one plane,with the power decreasing with elevation angle relative to the plane;however, the antenna can alternatively be an isotropic antenna that hasa spherical radiation patent. Other variations of the antenna caninclude any appropriate antenna that can be integrated with the formfactor of the transmitting unit, while providing appropriatecommunication with external devices.

The radio 134 functions to transmit and receive signals from the antenna132, and also facilitates communication with elements of thetransmitting unit 130 and external devices. The radio 134 and theantenna 132 can additionally or alternatively be supplemented with alinking interface 136, as described in further detail below, but canadditionally or alternatively interface with other elements of theelectronics subsystem 120.

The linking interface 136 functions to transmit an output of at leastone element of the microsensor patch 110/transmitting unit 130 assemblyto a mobile computing device 150. Additionally, the linking interface136 can function to transmit and output of at least one element of themicrosensor patch 110 and transmitting unit 130 assembly to anotherelement external to the microsensor patch 110 and transmitting unit 130.Preferably, the linking interface 136 is a wireless interface; however,the linking interface 136 can alternatively be a wired connection. In afirst variation, the linking interface 136 can include a first modulethat interfaces with a second module included in a mobile computingdevice 150 or other external element (e.g., wrist-borne mobile computingdevice, head-mounted mobile computing device), wherein data or signals(e.g., microsensor or transceiver outputs) are transmitted from thetransmitting unit 130 to the mobile computing device 150 or externalelement over non-wired communications. The linking interface 136 of thefirst variation can alternatively implement other types of wirelesscommunications, such as 3G, 4G, radio, or Wi-Fi communication. In thefirst variation, data and/or signals are preferably encrypted beforebeing transmitted by the linking interface 136. For example,cryptographic protocols such as Diffie-Hellman key exchange, WirelessTransport Layer Security (WTLS), or any other suitable type of protocolcan be used. The data encryption can also comply with standards such asthe Data Encryption Standard (DES), Triple Data Encryption Standard(3-DES), or Advanced Encryption Standard (AES). In variations with dataencryption, data can be unencrypted upon transmission to the mobilecomputing device 150 associated with the user. However, in analternative variation, data can remain encrypted throughout transmissionto a mobile computing device (associated with the user, not associatedwith the user) and unencrypted at another module of a processingsubsystem 160 (e.g., unencrypted in the cloud), wherein informationderived from analysis of the data can then be transmitted back to themobile computing device associated with the user in a secure manner. Inthis variation, a user can thus pair his/her microsensor patch 110 witha mobile computing device unassociated with the user for transmission ofencrypted data, and then later receive personalized body information athis/her own mobile computing device 150 after processing in the cloud.

In a second variation, the linking interface 136 is a wired connection,wherein the linking interface 136 includes a wired jack connector (e.g.,a ⅛″ headphone jack, a USB connection, a mini-USB connection, alightning cable connection, etc.) such that the transmitting unit 130can communicate with the mobile computing device 150 and/or an externalelement through a complementary jack of the mobile device and/orexternal element. In one specific example of the linking interface 136that includes a wired jack, the linking interface is configured only totransmit output signals from the transmitting unit 130/microsensor patch110. In another specific example, the linking interface 136 isconfigured to transmit data to and from at least one element oftransmitting unit 130/transdermal path 110 assembly and a mobilecomputing device 150. In this example, the linking interface 136 cantransmit output signals into the mobile computing device 150 through aninput of the jack of the mobile computing device 150 and can retrievedata from an output of the jack of the mobile computing device 150. Inthis example, the linking interface 136 can communicate with the mobilecomputing device 150 via inter-integrated circuit communication (I2C),one-wire, master-slave, or any other suitable communication protocol.However, the linking interface can transmit data in any other way andcan include any other type of wired connection that supports datatransfer between the transmitting unit 130 and/or microsensor patch 110,and the mobile computing device 150.

As noted above, the electronics subsystem 120 can include any othersuitable module(s) and/or be configured in any other suitable manner.For instance, the electronics subsystem 120 can include or be incommunication with an actuator configured to automatically perform anaction (e.g., vibration, provision of a biasing force) that biases themicrosensor into communication with interstitial fluid of the user, inresponse to detection of unsuitable impedance derived from comparisonbetween an impedance signal and an impedance threshold condition.

1.1.3 System—Housing

The housing 190 supports the microsensor 116 and the electronicssubsystem 120, and functions to facilitate robust coupling of themicrosensor patch 110 to the user in a manner that allows the user towear the microsensor patch 110 for a sufficient period of time (e.g.,one week, one month, etc.). The housing 190 can also function to protectelements of the microsensor patch 110 from physical damage over thelifetime usage of the microsensor patch 110. Preferably, at least oneportion of the housing 190 is flexible to facilitate adhesion to theuser and compliance with skin of the user as the user moves in his/herdaily life; however, at least a portion of the housing 190 canalternatively be rigid in order to provide more robust protectionagainst physical damage. In an embodiment where a portion of the housing190 is flexible, other elements of the microsensor patch 110 can also beflexible (e.g., using a thin film battery, using flexible electronics,etc.) to facilitate adhesion to the user and compliance as the usermoves about in his/her daily life. In one variation, the housing 190 cancomprise a single unit that entirely houses the microsensor 116 and theelectronics subsystem 120. In this variation, the housing 190 can beconfigured to couple to the user using any suitable coupling mechanism(e.g., adhesive coupling mechanism, strap-based coupling mechanism,etc.). However, in other variations, the housing 190 can alternativelybe modular and comprise a set of portions, each portion configured toenable coupling of the microsensor 116 to the user and/or to houseelements of the electronics subsystem 120. Modularity of the housing 190can thus allow portions of the system 100 to be disposable and/orreusable.

In one such modular variation of the housing 190, as shown in FIG. 9,the housing can comprise a first housing portion 191 and a secondhousing portion 196, wherein the first housing portion 191 is configuredto facilitate coupling of filaments of the microsensor 116 to the user,and the second housing portion 196 is configured to house elements ofthe electronics subsystem 120 and to couple the electronics subsystem120 to the microsensor 116 by way of the first housing portion 191. Assuch, the first housing portion 191 and the second housing portion 196of this variation are preferably configured to mate with each other in acomplementary manner (e.g., with a male-female coupling mechanism, witha magnetic coupling mechanism, with a latch-based coupling mechanism,with a lock-and-key based coupling mechanism, etc.). In a specificexample, as shown in FIGS. 10A-10B, the first housing portion 191′includes an opening 192′, and a second housing portion 196′ isinsertable into the opening of the first housing portion in a firstconfiguration, wherein coupling between the first housing portion 191′and the second housing portion 196′ provides a hermetic seal between thefirst housing portion 191 and the second housing portion 196. In moredetail, as shown in FIG. 10C, the first housing portion 191 can includean o-ring 193 (e.g., an o-ring molded onto the material of the firsthousing portion) at a perimeter of the opening 192, and a perimeterregion of the second housing portion 196 can include a recessed region197 that interfaces with the o-ring 193 in a manner that provides ahermetic seal. In this specific example, the opening 192 and the secondhousing portion 196 each have substantially circular footprints;however, the opening 192 and the second housing portion 196 canadditionally or alternatively have any other suitable footprints or beconfigured in any other suitable manner.

In the specific example, as shown in FIGS. 10A-10B, the first housingportion 191′ can comprise an adhesive substrate 91 having a microsensoropening 92, a microsensor interface substrate 93 superior to theadhesive substrate and configured to pass the microsensor 92 through themicrosensor opening 92, a coupling ring 94 configured to retain theposition of the microsensor interface substrate 93 relative to theadhesive substrate 91 and to provide an interface for mating with thesecond housing portion 196, and a flexible cover 95 ensheathing thecoupling ring 94, coupled to the adhesive substrate 91, and configuredto maintain coupling between the adhesive substrate 191, the microsensorinterface substrate 93, and the coupling ring 94. In relation to theconfiguration described above, the adhesive substrate 91 is configuredto facilitate adhesion of the microsensor patch 110 to the user at aninferior surface of the adhesive substrate, and the flexible cover 95 isconfigured to provide the opening 192′ that receives the second housingportion 192.

The second housing portion 196 of the specific example is rigid, andconfigured to form a shell about the electronics subsystem 120, whileincluding openings that provide access for a set of contacts 98 thatinterface the electronics subsystem 120 with the microsensor interfacesubstrate 93 when the first housing portion 191 is coupled to the secondhousing portion 196. In relation to the microsensor interface substrate93 of the first housing portion 191, and in relation to a circular (orotherwise axially symmetric) configuration of an interface between thesecond housing portion 196 and the opening 192 of the first housingportion 191, the microsensor interface substrate 93 of the specificexample can include a circular printed circuit board comprising a set ofconcentric ring contacts 97, as shown in FIG. 10A, that interfaceelectronics of the second housing portion 196 with filaments of themicrosensor 116. As such, the set of contacts 98 (e.g., digitalcontacts) of electronics of the second housing portion 196 can properlyinterface with the microsensor 116 in any rotational position of thesecond housing portion 196 within the first housing portion 191, asshown in FIG. 10B. In alternative variations of this specific examplehowever, orientation-unspecific coupling between the first housingportion 191 and the second housing portion 196 can be achieved in anyother suitable manner. In still alternative variations of this specificexample, the first housing portion 191 and the second housing portion196 can be configured to couple with a set orientation in order toensure proper communication between the microsensor 116 and theelectronics subsystem 120.

In variations of the housing 190 comprising a first housing portion 191and a second housing portion 196, the first housing portion 191 and thesecond housing portion 196 can be coupled together and/or coupled to theuser by way of a patch applicator 180, as described in further detailbelow. Furthermore, other variations of modularity can comprise anyother suitable distribution of the microsensor 116 and elements of theelectronics subsystem 120 across portions of the housing in any othersuitable manner. For instance, in one such variation, the microsensor116, the multiplexer 22, and the analog front end 93 of the electronicssubsystem 120 can be coupled to a separate battery (e.g., a thin filmbattery) within a disposable portion of the housing 190, and otherelements of the electronics subsystem 120 can be supported by a reusableportion of the housing 190. The system 100 can, however, comprise anyother suitable distribution of elements across the housing 190 in amodular fashion.

1.2 System—Processing Subsystem

The processing subsystem 160 is in communication with the electronicssubsystem 120 and functions to generate analyses pertaining to theuser's body chemistry, and to transmit information derived from theanalyses to the user at an electronic device associated with the user.As shown in FIG. 1, the processing subsystem 160 can be implemented inone or more of: a computer machine, a remote server, a cloud computingsystem, a microprocessor, processing hardware of a mobile computingdevice (e.g., smartphone, tablet, head-mounted mobile computing device,wrist-borne mobile computing device, etc.) and any other suitableprocessing system. In one variation, the processing subsystem 160comprises a first module 161 configured to generate an analysisindicative of an analyte parameter of the user and derived from a signalstream from the microsensor 116 and an impedance signal from theelectronics subsystem 120. Additionally, in this variation, theprocessing subsystem 160 comprises a second module 162 configured torender information derived from the analysis at an electronic device(e.g., mobile computing device 150) associated with the user, therebyfacilitating monitoring of body chemistry of the user. In thisvariation, the modules of the processing subsystem 160 can beimplemented in a hardware module and/or a software module. Invariations, a software module 163 can be implemented, at least in part,as a native software application executing on a mobile computing device150 associated with the user, wherein the user has a user accountassociated with the native software application.

In more detail, the software module 163 functions to analyze an outputprovided by the transmitting unit 130 of the electronics subsystem 120,and to communicate an analysis of the output back to the user, so thatthe user can monitor his/her body chemistry. Preferably, the softwaremodule 163 analyzes at least one analyte parameter in order to determinea metric providing information about a user's body chemistry. In onevariation, the software module can determine that a body analyteparameter (e.g., glucose level) of the user is too low or less thanideal, and facilitate a behavior change in the user by providing a bodychemistry metric indicating a hypoglycemic state. In this variation, thesoftware module can additionally determine that the body analyteparameter (e.g., glucose level) of the user is within a proper rangebased on a determined metric. The software module of this variation canadditionally determine that the body analyte parameter (e.g., glucoselevel) of the user is too high and facilitate a behavior change in theuser by providing a body chemistry metric indicating a hyperglycemicstate.

In another example, the software module can analyze an output providedby the transmitting unit 130 based on a set of parameters for multipleanalytes characterizing a user's body chemistry, at a set of timepoints, and determine at least one metric based on the set of parametersat the set of time points. The software module can then determine andoutput at least one of a temporal trend in a metric, a temporal trend inan analyte parameter, absolute values of a metric, changes in value of ametric, absolute values of an analyte parameter, and changes in value ofan analyte parameter. The software module 163 in this example canfurther be configured to communicate a suggestion to the user based onan analysis determined from the set of parameters for multiple analytes.

The software module preferably incorporates at least one of user healthcondition, user characteristics (e.g., age, gender, ethnicity), and useractivity in analyzing an output provided by the transmitting unit 130.In one specific example, if a user sets a desired body glucose levelrange, which is entered into the software module, the software modulecan be configured to facilitate provision of alerts notifying the userof short-term risks (e.g., diabetic crash), long-term risks (e.g.,worsening diabetic condition), and risk of exiting the desired bodyglucose level range. In another specific example, the software modulecan compare analyte parameters and/or a metric characterizing the user'sbody chemistry to other users with similar health conditions orcharacteristics (e.g., age, gender, ethnicity). In yet another example,the software module can be able to correlate at least one analyteparameter or metric to a user activity, such that the user is providedwith information relating a value of the analyte parameter and/or metricto an activity that he or she has performed. The software module canadditionally or alternatively provide an analysis that includes anyother health- and/or user-related information that can be useful intreating, maintaining, and/or improving a health condition of a user.

As shown in FIGS. 1, 11A, and 11B, the software module can beimplemented, at least in part, as an application executable on a mobilecomputing device 150. As described above, the mobile computing device150 is preferably a smartphone but can also be a tablet, laptopcomputer, PDA, e-book reader, head-mounted computing device,smart-watch, or any other mobile device. The software module canalternatively be an application executable on a desktop computer or webbrowser. The software module preferably includes an interface thataccepts inputs from the user (e.g., user health condition, usercharacteristics, user activity), and uses these inputs in analyzing anoutput provided by the transmitting unit 130. Preferably, the softwaremodule also includes an interface that renders an analysis based onsensed analytes and/or user inputs in some form. In an example, thesoftware module includes an interface that summarizes analyte parametervalues in some manner (e.g., raw values, ranges, categories, changes),provides a trend (e.g., graph) in at least one analyte parameter or bodychemistry metric, provides alerts or notifications, provides additionalhealth metrics, and provides recommendations to modify or improve bodychemistry and health metrics. In another example, the software modulecan implement two interfaces: a first interface accessible by a user,and a second interface accessible by a health care professionalservicing the user. The second interface can provide summarized anddetailed information for each user that the health care professionalinteracts with, and can further include a message client to facilitateinteractions between multiple users and the health care professional.The software module can additionally or alternatively access a remotenetwork or database containing health information of the user. Theremote network can be a server associated with a hospital or a networkof hospitals, a server associated with a health insurance agency ornetwork of health insurance agencies, a server associated with a thirdparty that manages health records, or any other user- or heath-relatedserver or entity. The software module can additionally or alternativelybe configured to accept inputs from another entity, such as a healthcareprofessional, related to the user.

The software module 163 can additionally or alternatively execute fullyor in part on a remote server. In a first variation, the software modulecan be a cloud-computing-based application that performs data analysis,calculations, and other actions remotely from the mobile computingdevice 150. In one example of the first variation, the mobile computingdevice 150 can receive an output of the transmitting unit 130 via thelinking interface 136 and then transfer the output to the remote serverupon which the software module executes. In the first variation, signalsare preferably transferred via a wireless connection, such as aBluetooth connection, 3G or 4G cellular connection, and/or via a Wi-Fiinternet connection. In another example of the first variation, a mobilecomputing device 150 can function to transmit data to and/or receivedata from the software module. In a second variation, the softwaremodule can include a first software component executable on a mobilecomputing device 150, such as an application that manages collection,transmission, retrieval, and/or display of data. In the secondvariation, the software module can further include a second softwarecomponent that executes on the remote server to retrieve data, analyzedata, and/or manage transmission of an analysis back to the mobilecomputing device 150, wherein the first software component managesretrieval of data sent from the second software component and/or rendersof a form of the analysis on a display of the mobile computing device150. However, the software module can include any number of softwarecomponents executable on any mobile computing device 150, computingdevice, and/or server and can be configured to perform any otherfunction or combination of functions.

As shown in FIG. 12A, the software module 163 can further be integratedwith a notification module 165 configured to provide an alert ornotification to a user and/or health care professional based on theanalysis of the output. The notification module 165 functions to accessan analysis provided by the software module and to control transmissionof a notification 166 to at least one of a user and a healthcareprofession interacting with the user. In one variation, the notificationmodule 165 receives an analysis of the software module being executed ona mobile computing device 150, and generates a notification 166 basedupon the analysis. In this variation, a form of the analysis ispreferably transmitted from the software module, executing on the mobilecomputing device 150, to the notification module 165, wherein the mobilecomputing device 150 accesses the analysis either from the softwaremodule executing on the mobile computing device 150 or from the softwaremodule executing on a remote server and in communication with the mobilecomputing device 150. The notification module 165 preferably controlstransmission of the notification 166 to the user, such as by triggeringa display of the mobile computing device 150 to display a form of thenotification, or by generating and/or transmitting an email, SMS,voicemail, social media platform (e.g., Facebook or Twitter) message, orany other message accessible by the user and which contains thenotification 166. The notification module 165 can also convey thenotification 166 by triggering a vibration of the mobile device 160,and/or by altering the state (i.e., ON or OFF) of one or more lightsources (e.g., LEDs) of the mobile computing device 150. However, thenotification module 165 can alternatively manage the transmission of anyother information and function in any appropriate manner.

The notification 166 preferably contains information relevant to a bodychemistry status of the user. The notification 166 can additionallyinclude an explicit directive for the user to perform a certain action(e.g., eat, rest, or exercise) that affects the body chemistry of theuser. Therefore, the notification 166 preferably systematically andrepeatedly analyzes a body chemistry status of the user based on atleast one analyte parameter of the user and provides and alert and/oradvice to manage and monitor a user's body chemistry substantially inreal time. In one example, the notification 166 can further includeinformation related to what or how much to eat, where and how long torun, level of exertion, and/or how to rest and for how long in order toappropriately adjust body chemistry. In other examples, the notification166 can include any appropriate information relevant to monitoring abody chemistry metric of the user.

In still other examples, as shown in FIG. 12B, the notification 166 canindicate one or more of: a current level of a measured analyte (e.g.,represented in hue, represented in saturation, represented in intensity,etc. of a graphical rendering); a trending direction for the level ofthe measured analyte (e.g., represented in a feature gradient within agraphical rendering); a lower bounding level and an upper bounding levelbetween which the level of the measured analyte is traversing; atrending direction of a level of a measured analyte (e.g., representedin an arrow of a graphical rendering); a quantification of a level of ameasured analyte (e.g., represented as rendered text); a summary of alevel of a measured analyte (e.g., represented as rendered text); apercent of time within a time duration (e.g., one day) that the level ofthe measured analyte is within a target range (e.g., healthy range); andhistorical behavior of a level of a measured analyte (e.g., representedas historical “ghosting” of a rendering based upon a previous analytelevel).

Additionally or alternatively, in still other examples, as shown in FIG.12C, the notification 166 can include a graphical rendering that showsanalyte data from past to present using a line graph representation,wherein an amount (e.g., concentration) of the analyte is representedalong a first axis and time is represented along a second axis. In theseexamples, the graphical rendering can further include a “predictedregion” based upon the analysis of the processing subsystem 160, whereinthe predicted region 66 depicts a prediction of where the analyte levelwill be at a future time point, and a width of the predicted region 66indicates confidence in the prediction.

In relation to the processing subsystem 160 and analyses generated atthe processing subsystem 160, the processing subsystem 160 can becoupled to or comprise a data storage unit 170, as shown in FIG. 13. Thedata storage unit 170 functions to retains data, such as an analysisprovided by a software module, a notification 166, and/or any otheroutput of any element of the system 100. The data storage unit 170 canbe implemented with the microsensor patch 110, transmitting unit 130,mobile computing device 150, personal computer, web browser, externalserver (e.g., cloud), and/or local server, or any combination of theabove, in a network configured to transmit, store, and receive data.Preferably, data from the data storage unit 170 is automaticallytransmitted to any appropriate external device continuously; however,data from the data storage unit 170 can alternatively be transmittedonly semi-continuously (e.g., every minute, hourly, daily, or weekly).In one example, data generated by any element can be stored on a portionof the data storage unit 170 when the linking interface 136 is notcoupled to an element external to the microsensor patch 110/transmittingunit 130 assembly. However, in the example, when a link is establishedbetween the linking interface 136 and an external element, data can thenbe automatically transmitted from the storage unit 170. In otherexamples, the data storage unit 170 can alternatively be prompted totransmit stored data by a user or other entity. Operation modes relatedto device pairing and information transfer are further described inrelation to the base station of Section 1.4 below.

1.3 System—Applicator

As shown in FIG. 1, the system 100 can further comprise a patchapplicator 180, which functions to facilitate application of at leastone of the microsensor patch 110 and the transmitting unit 130. Thepatch applicator 180 preferably accelerates the a portion of the housingwith the microsensor 116 toward skin of the user, thereby causing themicrosensor 116 to penetrate skin of the user and sensing regions of themicrosensor to access interstitial fluid of the user. However, the patchapplicator 180 can additionally or alternatively facilitate coupling ofthe microsensor 116 to the user using one or more of: skin stretching,skin permeabilization, skin abrasion, vibration, and/or any othersuitable mechanism, variations of which are shown in FIGS. 14A-14C. In afirst variation, as shown in FIG. 15A, the patch applicator 180′ can beincorporated into a first housing portion 191 of a housing 190 of thesystem 100 and can comprise an elastic pin 181 (e.g., spring-loaded pin)configured to complement a recess of a second housing portion 196. Inthis variation, a normal force applied to a broad surface of the secondhousing portion 196 initially causes the elastic pin 181 to retract, andrebounding of the elastic pin 181 into the recess of the second housingportion 196 biases and accelerates the microsensor 116 into the skin ofthe user.

In a second variation, as shown in FIG. 15B, the patch applicator 180″implements elastic portions of the housing 190, which can be used toretract a housing portion with the microsensor 116 and to release thehousing portion, thereby accelerating the microsensor 116 into skin ofthe user.

In a third variation, the patch applicator cooperates with a firsthousing portion 191 and a second housing portion 196, wherein the patchapplicator comprises a first applicator portion configured to surroundthe housing 190 and interface with the second housing portion 196, and asecond applicator portion configured to accelerate the second housingportion toward skin of the user. In a first specific example of thethird variation, as shown in FIG. 16A, the patch applicator 180 acomprises a ram-and-catch mechanism, wherein twisting of a rotatablecomponent 83 of the patch applicator 180 a transitions a plunger 84 ofthe patch applicator 180 a from a resting configuration 84 a to a loadedconfiguration 84 b, as shown in FIGS. 16B and 16C, and pushing of therotatable component 83 of the patch applicator 180 a releases theplunger 84 back to the resting configuration 84 a (as shown in FIG.16D), thereby accelerating the microsensor 116 toward skin of the userduring application of the microsensor patch 110 to the user. In moredetail, in the first specific example, twisting of the rotatablecomponent 83 transitions the plunger 84 along ramped surfaces 85 of thepatch applicator 180 a to the loaded configuration 84 a, where theplunger 84 rests on triggers 86 of the patch applicator 180 a. Then, asshown in FIG. 16D, pressing of the rotatable component 83 provides anoutward biasing force on the triggers 86 (e.g., due to wedge-shapedmorphology of the triggers that interacts with a complementary portionof the rotatable component 83), thereby releasing the plunger 84 to theresting configuration 84 a. In this specific example, a set of ribs 87coupled to a wall of the patch applicator 180 surrounding the plunger 84maintain plunger alignment.

In a second specific example of the third variation, as shown in FIG.17, the patch applicator 180 b comprises an elastic component 89 housedwithin and coupled to a translating component 88 of the patch applicator180 b, wherein the translating component 88 comprises a plunger 84′ andis configured to translate along a first axis. The patch applicator 180b further comprises a trigger 188 coupled to a biasing spring 189 andconfigured to translate along a second axis perpendicular to the firstaxis, between a holding position 188 a and a releasing position 188 b.In the second specific example, the translating component 88 is biasedin holding position 188 a, and pushing of the translating component 88places a lateral biasing force on the trigger 188 against the biasingspring 189 (e.g., due to wedge-shaped morphology of the trigger 188 thatinteracts with a complementary portion of the translating component 88),thereby releasing the plunger 84′ to accelerate the microsensor 116toward skin of the user. In pushing the translating component 88,compression of the elastic component 89 creates a reverse biasing forcethat automatically releases the translating component 88 toward theresting configuration 88 a.

The patch applicator 180 can alternatively be configured to receive themicrosensor patch 110, to stretch the skin of the user isotropically intwo dimensions to facilitate application, and to push the microsensorpatch 110/transmitting unit 130 assembly onto the user's stretch skin.Still alternatively, the patch applicator 180 can include any othersuitable applicator, variations and examples of which are described inU.S. App. No. 62/025,174 entitled “System for Monitoring Body Chemistry”and filed on 16 Jul. 2014. Still other variations of the system 100 canentirely omit a patch applicator 180.

1.4 System—Base Station

As shown in FIG. 1, the system can include a base station 5 thatfunctions to receive the microsensor patch 110 (e.g., within a secondhousing portion 196). In receiving the microsensor patch 110, the basestation 5 can include alignment elements 6 (e.g., protrusions, recesses,magnetic alignment elements, etc.) that facilitate alignment of themicrosensor patch 110 within the base station, as shown in FIG. 18A. Thebase station 5 can additionally or alternatively facilitate charging ofa rechargeable battery of the microsensor patch 110 by includingelements that generate an electromagnetic field that interacts with acharging coil coupled to the battery, thereby charging the battery 138.The base station 5 can additionally or alternatively be used totransition the microsensor patch between different operational states,in relation to data transfer between the microsensor patch 110, a mobilecomputing device 150 associated with the user, and modules of aprocessing subsystem 160 (e.g., cloud module) as shown in FIG. 19. In afirst operation mode 5 a, the transmitting unit 130 of the microsensorpatch 110 and the mobile computing device 150 can pair/bond only whenthe second housing portion 196 of the microsensor patch 110 is incommunication with the base station 5 (e.g., aligned within the basestation 5). Thus, in the first operation mode 5 a, the microsensor patch110 can transmit and receive data (e.g., compact raw data compoundedinto a plurality of bits over Bluetooth communication). In a secondoperation mode 5 b wherein the microsensor patch 110 is not incommunication with the base station 5, the microsensor patch 110 can beconfigured to only transmit data (but not receive data), therebyreducing energy usage, preventing man-in-the-middle attack, andpreventing tampering. As such, the second operation mode 5 b preventsreading of data from the microsensor patch 110 by a fraudulent entity,without gaining physical access to the microsensor patch 110.

The operation modes of the system 100 enabled by the microsensor patch,the base station 5, the mobile computing device 150, and the processingsubsystem 160 are further detailed in FIG. 19. In relation to pairingwith the microsensor patch 110 in the first operation mode 5 a, themobile computing device 150 functions to provide one or more of: datarelay, data visualization, data storage, notification, and actionfunctions (e.g., as described in relation to the software module 163described above). In communicating information between the mobilecomputing device 150 and a cloud module of the processing subsystem 160,the mobile computing device 150 can be configured to transmit raw datain Javascript Object Notation (JSON) format (or any other suitableformat) to be processed in the cloud, and analyte data, notifications,and alerts (e.g., as derived from an analysis) can be transmitted backto the mobile computing device 150 in JSON format (or any other suitableformat). The cloud module of the processing subsystem 160 can thus serveto enable authentication of the user (e.g., in association with a useraccount of a native application) and/or data, data storage, dataprocessing, notification, and prediction functions, as described inrelation to the processing subsystem 160 described above. Thus, thesystem 100 is configured for fault tolerance, wherein the microsensorpatch 110 stores data when faulty operation of the mobile computingdevice 150 occurs, and failure of the processing subsystem 100 resultsin data storage at the mobile computing device. The system 100 can,however, be configured in any other suitable manner.

As shown in FIG. 18B, the base station 5 and the patch applicator 180can be configured to couple together, thus facilitating portability ofthe base station 5 and patch applicator 180. However, the base station5, patch applicator 180, and microsensor 110 can alternatively beconfigured to couple or not couple together in any other suitablemanner.

1.5 System—Calibration

The microsensor patch 110 is preferably calibrated to prevent signaldegradation and to mitigate the effects of transient effects experiencedduring analyte sensing. The primary sensing mechanism is potentiometricfor small analytes (e.g., potassium, sodium, calcium), and amperometricfor large molecules (e.g., glucose, lactic, creatinine). In a firstvariation, the microsensor patch 110 passively detects analytes bydetecting an impedance and/or capacitance change, as well as a voltagechange when an analyte or analyte concentration contacts the microsensor116. Calibration can occur by normalizing sensing measurements relativeto a grounded portion of the microsensor 116, such as a referenceelectrode.

In a second variation, the microsensor patch 110 can implement activeimpedance calibration, wherein a drive voltage is implemented by theelectronics subsystem 111 of the microsensor patch 110, and voltage andimpedance and/or capacitance changes are detected. The drive voltage ispreferably applied in a sinusoidal pattern, but can alternatively beapplied in any appropriate pattern. In the second variation, sensedanalytes or analyte concentrations are characterized by changes inimpedance, and noise is characteristically distinguished from analytedetection by monitoring changes in voltage unaccompanied by changes inimpedance or capacitance. The second variation thus employs aconductometric measurement to calibrate the microsensor patch 110.Impedance measurements can also be used to address shift in a referenceelectrode (e.g., in the first variation described above).

In a third variation, the microsensor patch 110 can employ injection ofa volume of a calibration solution with a known concentration of atleast one analyte, in order to calibrate the microsensor patch 110. Inan example of the third variation, the calibration solution can have aknown concentration of at least one analyte, such that changes (e.g.,changes in electrical parameters) detected by the microsensor patch 110in response to the calibration solution can be used to normalizemeasurements resulting from sensed analytes or analyte concentrationsoccurring after injection of the volume of calibration solution. In thethird variation, the calibration solution can be injected automaticallyand periodically over the lifetime usage of the transdermal patch;however, the calibration solution can alternatively be injected whenprompted by a user or other entity.

In a fourth variation, the microsensor patch 110 can include a membranecomprising a known concentration and/or release profile of at least oneanalyte, in order to calibrate the microsensor patch 110. In an exampleof the fourth variation, the membrane can have a known concentration andrelease profile of at least one analyte, such that changes (e.g.,changes in electrical parameters) detected by the microsensor patch 110in response to the membrane can be used to normalize measurementsresulting from sensed analytes or analyte concentrations. In the fourthvariation, the membrane can be a degradable membrane, such thatdegradation of the membrane over time releases analytes from themembrane. Alternatively, the membrane can be manufactured with specificporosity, contributing to a certain analyte release profile.

In a fifth variation, the microsensor patch 110 can include a coating ora cap comprising a soluble species (e.g., analyte/ion) with a well-knownsolubility, in order to calibrate the microsensor patch 110. In anexample of the fifth variation, the soluble species maintains a knownconcentration of the species within the vicinity of a filament that canbe used to normalize and/or calibrate a signal. Examples of solublespecies include low solubility, biocompatible calcium salts, such ascalcium carbonate, calcium phosphate, and dicalcium phosphate forcalcium sensing. Other suitable soluble species can be used to calibrateother analytes.

In alternative variations, the microsensor patch 110 can use any othersuitable calibration method. For instance, the transdermal patch can bepre-staged, prepped, loaded, or activated to have a set calibrationstate enabling calibration of the system after application to the userwithin a desired period of time (e.g., an 85 mg/dl calibration stateequilibrated after insertion within a period of 2 hours).

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the described embodiments, variations, and examples ofthe system 100 without departing from the scope of the system 100.

2. Method

As shown in FIG. 20, a method 200 for monitoring body chemistry of auser comprises: receiving a second housing portion into an opening of afirst housing portion S210, the first housing portion supporting amicrosensor including a first working electrode, a second workingelectrode, a reference electrode, and a counter electrode, and thesecond housing portion supporting an electronics subsystem configured toreceive a signal stream from the microsensor; after interfacing with thesecond housing portion, accelerating the second housing portion towardskin of the user S220, thereby delivering sensing regions of themicrosensor into interstitial fluid of the user; generating an impedancesignal, from two of the first working electrode, the second workingelectrode, the reference electrode, and the counter electrode, inresponse to applying a voltage, near a shifted potential different thana reference potential of the reference electrode S230, wherein theshifted potential is associated with a signal conditioning module of theelectronics subsystem; at a processing system in communication with theelectronics subsystem, receiving the signal stream and the impedancesignal S240; at the processing system, generating an analysis indicativeof an analyte parameter of the user and derived from the signal streamand the impedance signal S250; and transmitting information derived fromthe analysis to an electronic device associated with the user, therebyfacilitating monitoring of body chemistry of the user S260.

The method 200 functions to provide continuous monitoring of a user'sbody chemistry through reception and processing of signals associatedwith of one or more analytes present in the body of the user, and toprovide an analysis of the user's body chemistry to the user and/or anentity (e.g., health care professional, caretaker, relative, friend,acquaintance, etc.) associated with the user. Alternatively, the method200 can function to detect a user's body chemistry upon the user'srequest or sporadically, and/or can provide an analysis of the user'sbody chemistry only to the user. The method is preferably implemented,at least in part, using an embodiment, variation, or example of elementsof the system 100 described in Section 1 above; however, the method 200can additionally or alternatively be implemented using any othersuitable system.

Variations of the system 100 and method 200 include any combination orpermutation of the described components and processes. Furthermore,various processes of the preferred method can be embodied and/orimplemented at least in part as a machine configured to receive acomputer-readable medium storing computer-readable instructions and/orin the cloud. The instructions are preferably executed bycomputer-executable components preferably integrated with a system andone or more portions of a control module and/or a processor. Thecomputer-readable medium can be stored on any suitable computer readablemedia such as RAMs, ROMs, flash memory, EEPROMs, optical devices (CD orDVD), hard drives, floppy drives, or any suitable device. Thecomputer-executable component is preferably a general or applicationspecific processor, but any suitable dedicated hardware device orhardware/firmware combination device can additionally or alternativelyexecute the instructions.

The FIGURES illustrate the architecture, functionality and operation ofpossible implementations of systems, methods and computer programproducts according to preferred embodiments, example configurations, andvariations thereof. In this regard, each block in the flowchart or blockdiagrams may represent a module, segment, step, or portion of code,which comprises one or more executable instructions for implementing thespecified logical function(s). It should also be noted that, in somealternative implementations, the functions noted in the block can occurout of the order noted in the FIGURES. For example, two blocks shown insuccession may, in fact, be executed substantially concurrently, or theblocks may sometimes be executed in the reverse order, depending uponthe functionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts, or combinations of special purpose hardware andcomputer instructions.

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the preferred embodiments of the invention withoutdeparting from the scope of this invention defined in the followingclaims.

We claim:
 1. A system for monitoring body chemistry of a user, thesystem comprising: a first housing portion supporting a microsensorcomprising a working electrode, a reference electrode, and a counterelectrode defined on a substrate and collectively operable to sense ananalyte within interstitial fluid of the user during use, the firsthousing portion comprising: an opening into an electrical interface withthe microsensor, and an adhesive region, surrounding the microsensor ata second surface opposing the electrical interface, the adhesive regioncoupleable to skin of the user, a second housing portion insertable intothe opening of the first housing portion in a first configuration, thesecond housing portion supporting: an electronics subsystem comprising asignal conditioning portion that receives and processes a signal streamfrom the microsensor upon sensing of the analyte in a sensing mode, thesignal conditioning portion configured with an operating potential at ashifted potential different than a reference potential of the referenceelectrode, wherein, during operation, the electronics subsystemrepeatedly transitions between the sensing mode and an impedancedetection mode, wherein in the impedance detection mode, the electronicssubsystem: applies a voltage near the shifted potential to the workingelectrode, and measures an impedance signal between the workingelectrode and the reference electrode; and an applicator operable toaccelerate and expel the second housing portion and the first housingportion from the applicator and onto the user, with the adhesive regionand a filament array of a microsensor oriented toward skin of the user,thereby coupling the first and the second housing portions to the userand causing the microsensor to penetrate skin of the user prior tocoupling of the adhesive region to the user.
 2. The system of claim 1,wherein during the sensing mode, the electronics subsystem continuouslydetects a voltage parameter of the counter electrode and, in cooperationwith a processing system: generates a comparison between the voltageparameter and a voltage threshold condition, and applies the appliedvoltage in the impedance detection mode based upon the comparison. 3.The system of claim 1, further comprising a processing subsystem incommunication with the electronics subsystem and operable in: a firstmode that generates an analysis indicative of an analyte parameter ofthe user and derived from the signal stream and the impedance signal,and a second mode that render information derived from the analysis atan electronic device associated with the user, thereby facilitatingmonitoring of body chemistry of the user.
 4. The system of claim 1,wherein, in the impedance detection mode, the electronics subsystemapplies the voltage having a characteristic value centered about theshifted potential and a sinusoidal waveform, upon detection of a voltagecondition at the counter electrode.
 5. The system of claim 1, furthercomprising a processing system in communication with the electronicssubsystem and an electronic device of the user, wherein, in relation totransitioning between the sensing mode and the impedance detection mode,the processing subsystem generates a notification at the electronicdevice of the user in response to detection of unsuitable impedancederived from a comparison between the impedance signal and an impedancethreshold condition.
 6. The system of claim 1, wherein in relation totransitioning between the sensing mode and the impedance detection mode,an actuator coupled to the electronics subsystem automatically providesa vibrational force that biases the microsensor into communication withinterstitial fluid of the user, in response to detection of unsuitableimpedance derived from comparison between the impedance signal and animpedance threshold condition post an initial application of themicrosensor into the user.
 7. The system of claim 1, further comprisinga reused mode wherein the first housing portion is disposed anduncoupled from the second housing portion, and wherein the secondhousing portion is coupled to a second instance of the first housingportion.
 8. A system for monitoring body chemistry of a user, the systemcomprising: a first housing portion supporting a microsensor comprisinga working electrode, a reference electrode, and a counter electrodedefined on a substrate and collectively operable to sense an analytewithin interstitial fluid of the user during use, the first housingportion comprising: an opening into an electrical interface with themicrosensor, and an adhesive region, surrounding the microsensor at asecond surface opposing the electrical interface, the adhesive regioncoupleable to skin of the user; and a second housing portion insertableinto the opening of the first housing portion in a first configuration,the second housing portion supporting: an electronics subsystemcomprising a signal conditioning portion that receives and processes asignal stream from the microsensor upon sensing of the analyte in asensing mode, the signal conditioning portion configured with anoperating potential at a shifted potential different than a referencepotential of the reference electrode, wherein, during operation, theelectronics subsystem repeatedly transitions between the sensing modeand an impedance detection mode, wherein in the impedance detectionmode, the electronics subsystem: applies a voltage near the shiftedpotential to an electrode subset comprising at least one the workingelectrode and the counter electrode, and measures an impedance signalbetween the electrode subset and the reference electrode.
 9. The systemof claim 8, wherein during the sensing mode, the electronics subsystemcontinuously detects a voltage parameter of the counter electrode and,in cooperation with a processing system: generates a comparison betweenthe voltage parameter and a voltage threshold condition, and applies theapplied voltage in the impedance detection mode based upon thecomparison.
 10. The system of claim 8, wherein the microsensor comprisesa second working electrode defined on the substrate.
 11. The system ofclaim 8, further comprising a reused mode wherein the first housingportion is disposed and uncoupled from the second housing portion, andwherein the second housing portion is coupled to a second instance ofthe first housing portion.
 12. The system of claim 8, wherein themicrosensor comprises an array of microfilaments, each filament in thearray comprising i) a substrate core extending from the substrate andcomprising a columnar protrusion having a base end and a distal portionoperable to provide access to interstitial fluid of the user during use;ii) a conductive layer, isolated to the distal portion of the substratecore and away from the base end and operable to transmit electronicsignals generated upon detection of the analyte; iii) an insulatinglayer surrounding the substrate core and exposing a portion of theconductive layer at the distal portion; and iv) a sensing layer coupledto the conductive layer and operable to sense the analyte.
 13. Thesystem of claim 12, wherein the the microsensor comprises a selectivelayer, having a distribution of molecules that interact with theanalyte, coupled to the sensing layer.
 14. The system of claim 8,wherein at least one of the microsensor and the electronics subsystemcomprises a temperature sensor operable to measure body temperature ofthe user during use of the system.
 15. The system of claim 8, furthercomprising a processing subsystem in communication with the electronicssubsystem and operable in: a first mode that generates an analysisindicative of an analyte parameter of the user and derived from thesignal stream and the impedance signal, and a second mode that renderinformation derived from the analysis at an electronic device associatedwith the user, thereby facilitating monitoring of body chemistry of theuser.
 16. The system of claim 15, further comprising: at the processingsubsystem, rendering a present state of the analyte parameter,indicating a future state toward which the analyte parameter ispredicted to trend, and a percent of time value within a time durationat which values of the analyte parameter are within a target range,wherein the values of the analyte parameter comprise future state valuesof the analyte parameter.
 17. The system of claim 8, wherein theelectrical interface of the first housing portion comprises a set ofconcentric ring contacts configured to interface electronics of thesecond housing portion with filaments of the microsensor, in any rotatedconfiguration of the second housing portion within the opening of thefirst housing portion.
 18. The system of claim 8, further comprising acharging and data transfer mode, wherein transitioning to the chargingand data transfer mode is triggered upon positioning the second housingportion, with the electronics subsystem into proximity with a basestation, wherein, in the charging and data transfer mode, a battery ofthe electronics subsystem is charged by the base station and data istransferred between the electronics subsystem and a mobile computingdevice associated with the user.
 19. The system of claim 8, furthercomprising an applicator operable to accelerate and expel the secondhousing portion and the first housing portion from the applicator andonto the user, with the adhesive region and a filament array of amicrosensor oriented toward skin of the user, thereby coupling the firstand the second housing portions to the user and causing the microsensorto penetrate skin of the user prior to coupling of the adhesive regionto the user.
 20. The system of claim 19, wherein accelerating the secondhousing portion and the first housing portion comprises, in response toa user interacting with a trigger of an applicator, transitioning aplunger of the applicator from a resting state to a loaded configurationwith the plunger contacting the second housing portion, and releasingthe plunger to accelerate the second housing portion toward skin of theuser along a first axis perpendicular to the skin of the user, whereinthe applicator and the plunger are arranged exterior the first and thesecond housing, and wherein the applicator surrounds the first and thesecond housing portion.